The present invention relates to methods and systems for reducing the incidence of complications that occur following many common surgical procedures. More particularly, the present invention relates to systems for reducing post-surgical complications that occur due to the natural tendency of the human body to form adhesions between injured areas within body cavities.
As a result of the healing process that follows abdominal, cardiothoracic, or arthroscopic surgery, complications frequently arise due to the natural tendency of the human body to form adhesions, which are connective tissue structures between injured areas within body cavities. Adhesions may form regardless of the nature of surgical procedures, whether done in a so-called minimally invasive fashion using laparoscopy or with a standard technique involving one or more relatively large incisions. These connective tissue bridges may cause various, often serious, complications. Usually the relief of post-surgical complications caused by adhesions requires another surgery. The subsequent surgery is complicated by the adhesions that were formed as a result of the previous surgery. The second surgery, itself, is likely to result in further adhesions and a continuing cycle of additional surgical complications.
One example of a problem that can be caused by adhesions is that following abdominal surgery, loops of intestine may become entangled or twisted about these adhesions. The entanglements may cause partial or total flow obstruction through the bowel, or may compromise the blood flow to and from the bowel. If such a condition is not relieved rapidly, the bowel dies and shortly thereafter the condition may cause death of the afflicted patient. As another example, adhesions that form in the pelvis after obstetric or gynecologic surgery may cause sterility as well as chronic pain.
Various suggestions have been made to avoid, reduce, or eliminate the formation of adhesions. For instance, standard surgical procedure in the United States often includes the steps of washing powder from surgical gloves prior to surgical operations, using powder-free gloves, and washing body cavities thoroughly prior to closing incisions. Another of the strategies that has been suggested to prevent adhesion formation is to loosely place a non-reactive barrier between an injured peritoneal surface and internal organs. Materials such as Interceed(trademark) and Seprafilm(trademark) and methods as described in U.S. Pat. No. 5,791,352 to Reich et al., have been advocated for minimizing adhesions. Also pourable (solidifying liquid gel material) substances have been suggested for preventing adhesion formation. These measures, unfortunately, have had only modest success in reducing the formation of post-surgical adhesions at the surgical locations. Therefore, it would be desirable to provide new and improved methods and apparatus that would eliminate or minimize adhesions.
The present invention provides systems and methods for reducing the incidence of post-surgical tissue adhesions resulting from surgical incisions or perforations. In particular the present invention is adapted to treat surgical incisions or perforation to the peritoneum. The method of the present invention applies radio frequency (RF) energy to the edges of the peritoneal tissue that has been injured during surgery; the heat thus generated by RF energy minimizes or eliminates the formation of post-surgical adhesions.
During surgery, the peritoneum could be injured in at least two ways: (1) when punctures are made through peritoneum using a surgical device such as a trocar, and (2) with conventional incisions through the peritoneum. In accordance with the present invention, embodiments of delivery systems are provided which optimize the delivery of RF energy to incisions or punctures.
In one embodiment of the invention, the system for delivering the RF energy to the injured tissue is provided in conjunction with a trocar system. Electrodes for delivering RF energy to the injured tissue are positioned on the distal portion of the trocar sleeve. Further embodiments are provided deriving from this delivery system arrangement wherein the RF energy is provided by a separate RF source that is distant from the trocar or wherein the RF energy source is contained within a detachable unit that attaches to the top of a trocar. In the former embodiment, the source of electrical energy for generating RF signal can be an AC power source or a remotely located battery. In the latter embodiment, the detachable unit may contain both a small battery as well as the electrical circuitry to provide the RF energy to the electrodes. The batteries may be changed once exhausted, or if the batteries are integral to the detachable unit, the entire unit may be disposed of once the battery is exhausted.
In an alternative embodiment delivery electrodes may be placed on a separate member utilized in conjunction with a trocar or similar cannula. For example, electrodes may be positioned on a rod which is sized to be inserted through the cannula and extend distally to expose the electrodes for treatment. Alternatively, a sleeve may be provided with distal electrodes, wherein the sleeve is sized to be slipped over the outer diameter of the cannula and thus position the electrode for treatment.
In another embodiment of the invention, the system for delivering RF energy to incised peritoneum comprises electrodes embedded into an insulating surgical sheath. The underside of the sheath may have a weakly bonding adhesive layer that allows the sheath to attach to the skin. The adhesive allows the sheath to be placed and attached over the site of an incision before cutting occurs. Within the sheath, a configuration of electrodes is placed in position such that after the surgeon cuts through the sheath, the underlying skin and peritoneum, the electrodes are positioned over the site of incision. Within seconds or minutes of the incision, RF energy is delivered through the electrodes to treat the incised peritoneal tissue. Incision edges also may be treated by contact with electrodes on a hand held wand.
Methods are provided for the controlled delivery of optimal dosages of RF induced heat to the affected tissues. In accordance with an aspect of the invention, the change in the impedance of the heated peritoneal tissue can be used to determine the completion of treatment. Circuitry may be employed to measure the tissue impedance using the RF electrodes in order to determine when the tissue impedance has increased to a level where the treatment should be terminated. Another means for determining the end of treatment is by measuring the temperature of the surrounding tissue using a thermocouple. Once a predetermined temperature is reached, the sensing and control circuitry turns off the RF energy delivery to the electrodes. In another variation, the RF delivery is turned off after a predetermined time duration has been reached. A further refinement tracks both the temperature of the heated tissue and the duration of the RF energy delivery in order to determine the end of treatment.